1. Field of the Invention
The present invention relates to a cooling means for heat-generating electronic components, preferably of an endoscope.
2. Discussion of the Prior Art
Electronic parts such as photosensitive sensors, light-emitting diodes (LED) etc. have been increasingly employed in medical apparatuses, for instance in endoscopic instruments. Endoscopes usually have at their distal end a visual means in the form of a photosensitive microchip, an optical means arranged upstream as well as a lighting means. Especially in such instruments it is necessary to compensate the heat caused by the lighting means as well as by the body temperature itself by appropriate cooling means or to protect the photosensitive electronic components against overheating by suitable insulation.
Therefore, from DE 196 26 433 A1 an endoscope head for an endoscope suited for diagnostic and therapeutic purposes in body cavities comprising a lighting means, an optical means as well as an image detecting means has become known which includes light-emitting elements disposed at its distal face and an integrated image forming means behind endoscope optics. Moreover, according to this prior art a cooling means is provided for passing through a cooling fluid, the cooling fluid being passed by the image forming means. In this way it is achieved that the heat-sensitive image detecting means is protected against overheating so as to hereby improve the image quality as a whole.
However, it has turned out that the cooling of the image forming means itself is insufficient as regards the overall function of an endoscope head of this species. As already explained in the beginning, such endoscope heads are equipped with a plurality of electronic and hydraulic/pneumatic means, where appropriate, which must not be exposed to thermodynamic loads or may only be exposed to small thermodynamic loads. In particular the focusing device of the endoscope optics is especially heat-sensitive, because in the case of an increase in temperature an optimum adjustment of the optical elements is no longer possible.
In order to solve this problem, from US 2005/0075538 A1 an endoscope of the one-way type has become known which equally utilizes a cooling means for electronic components, but this cooling means is associated with the LED. In other words, the LED are designed as part of the cooling means which is formed such that it can be fitted into a front cap of the endoscope in which also the other components specific to the endoscope such as optics, spraying means and the like are accommodated.
To this end, the cooling means is in the form of a semi-cylindrical collar into which plug-in connections for the LED are integrated and which shows mounts for receiving the LED at its end face. Moreover, hereby the entire optics including the lens system as well as photosensitive sensor are enclosed by the cooling means and are thus thermally shielded against the LED.
The inventor of the present invention found, however, that this special design of the cooling means further reduces the construction space which is extremely restricted in endoscopes anyway. Moreover the LED according to this prior art are still capable, despite the cooling, of contacting tissue of the body cavity to be examined and possibly of causing even burnings, depending on the alignment.
Therefore, it is the object of the present invention to provide a generic cooling means for electronic components, especially for use in medical instruments, which features a higher efficiency especially also for avoiding damage of tissue.
This object is achieved by a generic cooling means comprising the features according to the enclosed claim 1.